%0 Journal Article
%A Touahri , Sofiane
%A Boufendi, Toufik
%D 2015
%I Begell House
%K laminar mixed convection, concentric pipes, conjugate problem, numerical simulation
%N 11
%P 1019-1038
%R 10.1615/HeatTransRes.2015005019
%T CONJUGATE HEAT TRANSFER WITH VARIABLE FLUID PROPERTIES IN A HEATED HORIZONTAL ANNULUS
%U http://dl.begellhouse.com/journals/46784ef93dddff27,58e7376c20e25ba0,79ac00a20d3fc6e7.html
%V 46
%X In the present work, we numerically study the three-dimensional conjugate heat transfer in an annular space between two horizontal concentric cylinders; the outer cylinder is subjected to an internal energy generated by the Joule effect through its thickness while the inner is adiabatic. The thermal convection in the fluid domain is conjugated to the thermal conduction in the solid. The physical properties of the fluid are thermally dependent. The heat losses from the external outside pipe surface to the surrounding medium are considered. The model equations of continuity, momentum, and energy are solved numerically by a finite volume method with a second-order spatial-temporal discretization. The results obtained show the three-dimensional aspect of the thermal and dynamical fields with considerable variations of the viscosity and moderate variations of the fluid thermal conductivity. As expected, the mixed convection Nusselt number becomes more superior to that of forced convection when the Grashof number is increased. At the solid−fluid interface, the results clearly show the azimuthal and axial variations of the local heat flux and the local Nusselt numbers. Following these results, we have tried to model the average Nusselt number as a function of the Richardson number. With the parameters used, the heat transfer is quantified by the following correlation: Nu_{A}= 9.9130 Ri^{0.0816}.
%8 2015-08-28